KWhyear

KWh/year, short for kilowatt-hours per year, is a unit used to quantify the amount of electrical energy that is consumed or produced over the course of a year. It combines the energy unit kilowatt-hour with the time unit year to express annual energy activity. While it includes a time component, kWh/year is an energy total for a year rather than a continuous power rate.

To relate kWh/year to power, divide the annual energy by the number of hours in a year. The resulting value is the average power in kilowatts. Using 8,760 hours per year as a standard, 1 kWh/year corresponds to about 0.114 watts of continuous average power (1 kWh/year ÷ 8,760 h ≈ 0.114 W). Conversely, a device with 1 kW of continuous average power would use about 8,760 kWh in a year.

Common usage includes expressing the annual energy consumption of appliances and buildings, as well as annual energy production for solar photovoltaic systems. Manufacturers and labeling schemes often report energy use in kWh/year to facilitate comparisons and long-term budgeting. In solar contexts, systems are described by their expected annual generation in kWh/year, which depends on system size, location, and conditions.

Examples help illustrate the concept. A 9 W LED light on continuously for a year would consume about 78.8 kWh/year. An appliance with an annual energy use of 500 kWh/year has an average power draw of roughly 57 W. Actual energy use varies with usage patterns, climate, and efficiency.

See also: energy unit, kilowatt-hour, watt, annual energy consumption, energy efficiency.